China’s Censors Take on Virtual Private Networks

Users and providers try to stay one step ahead of China’s censors to keep the online workaround effective.

By Zach Toombs for The Diplomat

November 06, 2014

Like for so many others in China, using a virtual private network (VPN) has become part of Rett Marie’s daily routine. As the web editor of a Beijing expat magazine, it’s both a personal tool and a professional necessity.

“I’m almost always on VPN,” Marie says. “For my work, this is especially important as the expat community is still very much on international social media platforms.”

For two years, censors have done all they can to make VPNs an unworkable technology in China. Lokman Tsui is the former head of Free Expression at Google’s Asia Pacific branch. He says censors have taken a kitchen sink approach in blocking VPNs.

“Their perspective is a pragmatic one: let’s use whatever works, including but not limited to software, hardware, laws and policies and market incentives,” Tsui says by email.”

To some degree, it worked. The initial crackdown sent users in search of new alternatives. But two years later, VPNs remain effective and popular in China, partly because private network providers have created VPNs that no longer look like VPNs when they cross the Great Firewall.

“In the last couple years, the Great Firewall has gotten much better at identifying VPN protocols via deep packet inspection of Internet traffic,” says Andrew Staples of GoldenFrog, a company known for its VyprVPN service.

Staples describes this online arms race between China’s censors and companies like GoldenFrog as a “cat-and-mouse game.” Each party has adapted over the last two years to stay one step ahead.

GoldenFrog does this by scrambling OpenVPN packet metadata to ensure it’s not recognizable to censors.

“No technology is perfect,” Staples says. “But the results have been very good.”

GoldenFrog’s VyprVPN is among several top-rated VPN services, including WiTopia, Astrill and VPNinja, that have remained popular even during China’s anti-VPN campaign.

Censors have made improvements to their own technology, though by their nature those improvements are considerably tougher to document.

Michel Hockx, a professor at the University of London’s School of Oriental and African Studies, notes rumors that the Chinese government had begun filtering VPN traffic. That would mean censors not only identified VPNs but selectively limited web traffic through them.

Some netizens said the South China Morning Post, specifically, was blocked even for VPN users.

“It’s speculation, but it would mean China’s government actually monitored traffic going through those VPNs, which would really be an achievement,” says Hockx, author of “Internet Literature in China.”

And Tsui, now a journalism professor at the Chinese University of Hong Kong, makes an important point about China’s censors.

“Has it been effective? Let’s not forget that their goal is not to have a 100 percent perfect block. Instead, the goal is to continue to raise the cost of circumvention, [so] that only people with enough technical sophistication (or money) can do this.”